fix: preserve special chars in compose env file generation

[9MidhunPM]

Fixes #4694

Problem

Special characters like $$, #, {, } in env var values were being
interpreted by the shell when writing the .env file, causing pa$$word
to become paword inside containers.

Root cause

getCreateEnvFileCommand in packages/server/src/utils/builders/compose.ts
was passing env var content through shell interpolation when writing to disk.

Fix

Base64-encode the env content in Node before passing it to the shell, then
decode via a quoted heredoc (<< 'DOKPLOY_EOF'). The quoted delimiter
prevents any shell interpolation of the payload.

Testing

Added apps/dokploy/__test__/compose/env-file-literals.test.ts which runs
the generated bash command and asserts these values survive intact:

• pa$$word
• !"#$%&/()=?
• {"nested":{}}
• MAIL_PASSWORD="abc#de"